Electricity and magnetism are linked, a moving magnetic field will induce an electric current in a wire. An electric current will make a compass move. These two forms of energy 'bounce off' each other and so can propogate through a vacuum. They are so closely linked, the only way to really think of them is two sides of the same force, so the term Electro-magnetism is used.
A subatomic particle with a negative electrical charge. See Atomic Structure. It is found in surrounding the Neutron. The Electron is much smaller than the a Proton and Neutron. In Beta radiation, the electron is what is ejected from the nucleus.
The number of wavelengths passing a particular point over time, generally measured in cycles per second, or Hertz. For example, if a wavelength is 10cm long and it is travelling at 10cm per second, one wavelength passes a particular point in one second. So, it has a frequency of 1 hertz. If the speed is doubled to 20cm per second, then the frequency becomes 2 hertz. The equation to describe this is Frequency = speed / wavelength.
"Formation of the Gut". The way that the gut forms from the blastula
'K' Reproductive strategy
There are two forms of reproductive strategy, known as K and R. In an R strategy, many offspring are produced but little care is given to each. In a K strategy, only a few offspring are produced, but a lot of parental care is given.
All organisms can be placed on a place on a line between these two extremes. In general, invertebrates are more 'R' and vertebrates are more 'K'. An oyster can produce 1/2 million eggs per year but they are just left to their own devices. An elephant has just one child every two years, but cares for it.
This is because of the level of intelligence required to rear offspring successfully. The most 'K' of all animals are the great apes. Some can only have one child every five years, but this has led them down a dead end, because monkeys, who are more 'R' than the apes can produce more offspring, but they are still 'K' enough to look after them well.
large cells, formed in blastula near yolk at vegetal pole